We plan to study cardiovascular risk factors among 500 premenopausal women and the change in risk factors during and following the menopause. Three different approaches are planned. 1) A cross-sectional study of 500 women ages 42+ at entry to the study to determine the relationship between risk factors, behavioral, psychosocial, and other environmental determinants. 2) A five year longitudinal followup of these women to evaluate changes over time in risk factors related to both the perimenopausal and postmenopausal period. 3) A longitudinal followup of the women following the menopause to determine the relationship between behavioral, hormonal, habits and risk factor changes. If this phase of the study is successful, longer term followup beyond the five year period is anticipated. The study will include a selection of a population sample of 500 women in Allegheny County who are premenopausal and aged 42+. We estimate that over five years at least 200 of these women will become postmenopausal. The women will have home interviews, baseline examination, followup of their menstrual cycles, and a six month self-administered questionnaire will be included. Menopause will be defined as one year of amenorrhea, validated by hormonal studies. The perimenopausal period as the first three months of amenorrhea. A perimenopausal examination followed by a postmenopausal examination and suitable control examinations will be included. Postmenopausal women will be followed with annual examinations. Dependent and independent variables to be measured include behavioral factors, exercise, cigarette smoking, nutrition, lipoproteins, blood pressure and hormones. The study should determine whether there is a group of women who become high risk in relation to cardiovascular and other diseases around the time of the menopause because of changes in risk factors and whether this group can be classified by behavioral, hormonal or genetic characteristics.